Feeding your Crayfish
Crayfish are omnivorous scavengers, feeding primarily on plants, algae and organic detritus. Crayfish do not often find sources of animal protein such as a dead fish, and such meals are very precious to them, aggressively defending such a meal against other scavengers.
But will crayfish actually kill and eat your fish? In an aquarium it is uncommon for crayfish to catch and eat healthy fish, though the odds on such an event depend on the size of aquarium, the number of fish in the aquarium, what species of crayfish is being kept, and even whether the crayfish is well fed or not. So while it is unlikely that a crayfish will catch your fish, there is a possibility, particularly where small or slow moving fish are concerned. Most of the time crayfish are seen eating a fish that fish was already dead or dying, and the crayfish was simply doing its natural duty of being a scavenger. Without knowing this, the aquarist might falsely accuse the crayfish of murder when he notices the crayfish chewing on the carcass.
Crayfish need to be fed a small amount of food every other day or so. Any excess food should be immediately removed. Foods to feed your crayfish include leafy green vegetables such as Romaine lettuce (or other varieties); dried seaweed like Nori; sinking pellet foods such as shrimp or algae pellets; flake food; and freeze dried or frozen foods such as fish, krill, tubifex worms, bloodworms, squid, clam, etc. I also give my crayfish each a pea once a week. Since animal protein is rarely encountered in the wild, it is best to feed crayfish mostly plant or algae based foods, and only supplement with animal flesh. However, some aquarists feed strictly shrimp pellets with no apparent problems.
If a crayfish remains soft for an extended period of time, i.e., for more than 2 days after molting, this can mean that it is not receiving enough calcium in its diet or that the pH or hardness of the water is too low. Transferring the soft specimen to water with high hardness can help if this is the problem, but it is best to avoid this problem by keeping crayfish in hard water and feeding them foods rich in calcium. There are some brands of foods specifically formulated for crustaceans that have a higher level of calcium added, such as JBL NovoCrabs Food Chips and Sera Crabs Natural Complete Diet. Calcium can also be added to other foods by dabbing moist food with a small amount of calcium carbonate powder before feeding your cray.
Crayfish sometimes die during the moulting process, a problem apparently caused by an iodine deficiency. Iodine, in the form of potassium iodide, can be added to the water on a weekly basis to alleviate problems with the molting process. Iodine drops sold for use in marine tanks work well for this, though a half dose rather than full dosage is all that is required. Foods that contain the algae Spirulina sp. or Chlorella sp. are naturally high in iodine and can be helpful as well.
But will crayfish actually kill and eat your fish? In an aquarium it is uncommon for crayfish to catch and eat healthy fish, though the odds on such an event depend on the size of aquarium, the number of fish in the aquarium, what species of crayfish is being kept, and even whether the crayfish is well fed or not. So while it is unlikely that a crayfish will catch your fish, there is a possibility, particularly where small or slow moving fish are concerned. Most of the time crayfish are seen eating a fish that fish was already dead or dying, and the crayfish was simply doing its natural duty of being a scavenger. Without knowing this, the aquarist might falsely accuse the crayfish of murder when he notices the crayfish chewing on the carcass.
Crayfish need to be fed a small amount of food every other day or so. Any excess food should be immediately removed. Foods to feed your crayfish include leafy green vegetables such as Romaine lettuce (or other varieties); dried seaweed like Nori; sinking pellet foods such as shrimp or algae pellets; flake food; and freeze dried or frozen foods such as fish, krill, tubifex worms, bloodworms, squid, clam, etc. I also give my crayfish each a pea once a week. Since animal protein is rarely encountered in the wild, it is best to feed crayfish mostly plant or algae based foods, and only supplement with animal flesh. However, some aquarists feed strictly shrimp pellets with no apparent problems.
If a crayfish remains soft for an extended period of time, i.e., for more than 2 days after molting, this can mean that it is not receiving enough calcium in its diet or that the pH or hardness of the water is too low. Transferring the soft specimen to water with high hardness can help if this is the problem, but it is best to avoid this problem by keeping crayfish in hard water and feeding them foods rich in calcium. There are some brands of foods specifically formulated for crustaceans that have a higher level of calcium added, such as JBL NovoCrabs Food Chips and Sera Crabs Natural Complete Diet. Calcium can also be added to other foods by dabbing moist food with a small amount of calcium carbonate powder before feeding your cray.
Crayfish sometimes die during the moulting process, a problem apparently caused by an iodine deficiency. Iodine, in the form of potassium iodide, can be added to the water on a weekly basis to alleviate problems with the molting process. Iodine drops sold for use in marine tanks work well for this, though a half dose rather than full dosage is all that is required. Foods that contain the algae Spirulina sp. or Chlorella sp. are naturally high in iodine and can be helpful as well.